Numerical modeling of time-dependent cosmic-ray advection and diffusion in spherically symmetric wind bubbles shows escaping spectra harder than E^{-2} during the wind-driven phase, with low-energy suppression depending on the turbulence model.
Reconciling cosmic ray diffusion with Galactic magnetic field models
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
We calculate the diffusion coefficients of charged cosmic rays (CR) propagating in regular and turbulent magnetic fields. If the magnetic field is dominated by an isotropic turbulent component, we find that CRs reside too long in the Galactic disc. As a result, CRs overproduce secondary nuclei like boron for any reasonable values of the strength and the coherence length of an isotropic turbulent field. We conclude therefore that the propagation of Galactic CRs has to be strongly anisotropic because of a sufficiently strong regular field and/or of an anisotropy in the turbulent field. As a consequence, the number of sources contributing to the local CR flux is reduced by a factor ${\cal O}(100)$ compared to the case of isotropic CR diffusion.
fields
astro-ph.HE 2years
2026 2verdicts
UNVERDICTED 2representative citing papers
Simulations show that drift dominance over diffusion can create a knee at PeV energies if parallel diffusion becomes energy-independent above 1 TeV, though some setups fail to match observed grammage.
citing papers explorer
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Time-dependent cosmic-ray escape from wind bubbles: hard spectra formation
Numerical modeling of time-dependent cosmic-ray advection and diffusion in spherically symmetric wind bubbles shows escaping spectra harder than E^{-2} during the wind-driven phase, with low-energy suppression depending on the turbulence model.
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Transition from Diffusion to Drift-Dominated Cosmic Ray Transport and the Origin of the Knee
Simulations show that drift dominance over diffusion can create a knee at PeV energies if parallel diffusion becomes energy-independent above 1 TeV, though some setups fail to match observed grammage.